?Antioxidative system response of different wheat cultivars under drought: Field and in vitro studies

LASCANO, H.R., ; ANTONICELLI, G.E., ; LUNA, C.M. ; MELCHIORRE, M.N.,; RACCA, R.W. ; TRIPPI, V.S.; CASANO, L.M

AUSTRALIAN JOURNAL OF PLANT PHYSIOLOGY

Sciro Publishing

Año: 2001 vol. 28 p. 1095 - 1102

0310-7841

Abstract. The participation of the antioxidant system in the drought tolerance of wheat cultivars (Triticumaestivum L.) was studied under field and in vitro conditions. Under field conditions, drought tolerance was evaluatedby the capacity to maintain the grain yield under drought, which was higher in cvv. Elite and La Paz than in thesensitive cvv. Oasis and Cruz Alta. Tolerant cultivars showed lower relative water content (RWC) and lowerabove-ground vegetative biomass than sensitive cultivars. Field assays did not show a clear correlation betweenwater-stress tolerance and antioxidant system behaviour. However, when leaves of cvv. with contrasting droughttolerance were subjected to osmotic stress in vitro, clear differences in the antioxidant system activity and oxidativedamage between cvv. were observed. In the tolerant cultivar Elite, it was possible to observe an increase in ascorbateperoxidase (APX), superoxide dismutase (SOD) and glutathione reductase (GR) activities, a higher glutathione(GSH) and ascorbate content and less oxidative damage than in the sensitive cultivar Oasis, which showed nochanges or only slight decreases in the enzyme activities. These results indicate that water stress tolerance is in partassociated with the antioxidant system activity, and suggest that the behaviour of the antioxidant system in vitroassays can be used as an early selection tool.